In the discussion of the state of the art that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicants expressly reserve the right to demonstrate that such structures and/or methods do not qualify as prior art against the present invention.
Today, coated cemented carbide inserts with binder phase enriched surface zone as disclosed, e.g., in U.S. Pat. No. 4,277,283, U.S. Pat. No. 4,610,931 and U.S. Pat. No. 4,548,786, are commonly used for turning of metals and alloys. The binder phase enriched surface zone widens the application towards tougher cutting operations, but limits the thermal resistance and the wear resistance of the surface zone.
Generally, machining of short chipping materials with coated cemented carbide tools are made with inserts with a flat rake face, without chip breakers, or with simple chip breakers, which do not have binder phase enriched surface zones.
U.S. Pat. No. 4,610,931 discloses removal of binder phase enriched surface zones on the clearance face probably in order to improve flank wear resistance.